Powder for the autogenous soldering or welding of aluminum



- i Patented May 19, 1925.

UNITED STATES PATENT OFFICE.-

P10 ROSSI, OF BERNIE, SWITZERLAND.

Io Drawing.

To all whom it may concern Be it known that I Pro Rossr, a subject of the Kingdom of Italy, and residing at Berne, Switzerland, have invented a certain new and useful Powder for the Autogenous Soldering or Welding of Aluminum, of which the following is a specification.

My invention has for its object to provide a powder for the autogenous welding or solderin of aluminum, permitting welding,

soldering and repairs of all kinds to be made.

It has already been proposed to employ mixtures of chlorides and fluorides for the soldering and welding of aluminum. It has been found, however, that joints made with these mixtures are very liable to corrode and have a very low resistance against mechanical stresses.

Now, I have found that against corrosion and mechanical stresses very strong joints are produced by the use of a soldering powder obtained b a mixture comprising a small amount of ch oride of sodium and a large amount of chloride of potassium, to which 2:5 mixture is added a mixture consisting of equal parts by weight of fluoride of aluminum and cryolite and representing at least of the total mixture.

These ingredients are preferably em- 30 plo ed in the following proportions, viz:

Lhloride of sodium 100 parts by weight or Chloride of potassium 1150 parts by wei ht of 57.5%.

8 uoride of aluminum 875 parts by weight Cryolite 375 parts by weight or 18.75%.

The mixture may be made as follows Applloatlon filed June 5,

1928. Serial 1T0. 848,558.

First, the chlorides of sodium and potassium are worked up together, then the cryolite and fluoride of aluminum are added, and this mixture is worked up, until a homogeneous powder is obtained.

For using the owder it suflices to moisten it with a little a cohol and paint or daub it 45 with a brush or otherwise on the parts which are to be soldered or welded together, by means of the blow-pipe for example, either directly or with the aid of a stick of aluminum. 59

I 'claim:

1. A powder for the autogenous soldering or welding of aluminum, comprisin a mixture of a small amount of chloride 0 sodium and a large amount of chloride of potassium, and a fluoride mixture consisting of equal parts of fluoride of aluminum and cryolite and representing at least 35% of the total mixture.

2. A powder for the autogenous soldering or welding of aluminum formed of a mixture composed of the following ingredients in approximately the following proportions by weight, namely Partlo5 Chloride of sodium Chloride of potassium 1150 Fluoride of aluminum 375 Cryolite 375 In testimony whereof, aflix my signature in the presence of two witnesses.

, PIO ROSSI.

Witnesses A. Basrnwux, R. Hmrmummz. 

